{
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          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "fs/smb/server/smb2pdu.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
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              "version": "6.0"
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              "version": "6.6.145",
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            {
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              "status": "unaffected",
              "version": "6.12.97",
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            },
            {
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              "status": "unaffected",
              "version": "6.18.40",
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            },
            {
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              "version": "7.1.5",
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            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
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                  "vulnerable": true
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                {
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                  "vulnerable": true
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              "negate": false,
              "operator": "OR"
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      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: fix use-after-free of conn-\u003epreauth_info in concurrent SMB2 NEGOTIATE\n\nconn-\u003epreauth_info is shared connection state (struct\npreauth_integrity_info, kmalloc-96) that is allocated and freed by the\nSMB2 NEGOTIATE handler and read by the response send path.\n\nsmb2_handle_negotiate() allocates conn-\u003epreauth_info, and on a\ndeassemble_neg_contexts() failure kfrees it and sets it to NULL. Both the\nallocation and the free/NULL happen under ksmbd_conn_lock(conn) (the\nconnection srv_mutex), which is held across the whole handler body.\n\nThe response send path smb3_preauth_hash_rsp(), called from the send:\nblock of __handle_ksmbd_work(), reads conn-\u003epreauth_info and dereferences\nconn-\u003epreauth_info-\u003ePreauth_HashValue (via\nksmbd_gen_preauth_integrity_hash()) without taking conn_lock. When a\nclient drives two SMB2 NEGOTIATE requests on the same connection, one\nworker can free conn-\u003epreauth_info on the failing-negotiate path while a\nconcurrent send-path worker is reading it, producing a slab\nuse-after-free read (KASAN-confirmed).\n\nThe send-path read tested conn-\u003epreauth_info for NULL but raced with the\nfree that occurs between the NULL check and the dereference, so the NULL\nguard alone does not close the window.\n\nSerialize the NEGOTIATE-branch read in smb3_preauth_hash_rsp() under\nksmbd_conn_lock(conn) and re-check conn-\u003epreauth_info inside the lock.\nBecause the negotiate handler holds conn_lock across its kfree + NULL\nassignment, a reader that also takes conn_lock either runs fully before\nthe allocation or fully after the NULL store, and can never observe the\nfreed-but-not-yet-NULLed pointer. ksmbd_gen_preauth_integrity_hash()\ntakes no locks itself (it only computes a SHA-512 over the buffer), so\nno lock-ordering inversion is introduced, and conn_lock is a sleepable\nmutex which is safe on this send path (it already performs network I/O)."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 9.8,
            "baseSeverity": "CRITICAL",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:N - The bug is in ksmbd\u0027s SMB2 NEGOTIATE handler reachable by any remote client over TCP port 445 without local access; exploitation requires only crafted SMB 3.1.1 negotiate packets on an established network connection.\nAC:L - The attacker controls both sides of the race by pipelining two SMB2 NEGOTIATE requests on the same connection, with one crafted to fail deassemble_neg_contexts() and free preauth_info while the other is in the response send path; KASAN-confirmed UAF with no uncontrollable timing.\nPR:N - SMB2 NEGOTIATE is processed before any authentication or session establishment; smb2_check_user_session explicitly exempts NEGOTIATE from session validation, so an unauthenticated remote attacker can reach the vulnerable code path.\nUI:N - Exploitation requires only network packets sent by the attacker to an exposed ksmbd instance; no victim user action such as mounting a share or opening a file is needed.\nS:U - Successful exploitation compromises kernel memory on the SMB server host itself; this is standard in-kernel memory corruption without crossing a VM, container, or IOMMU security boundary to a separate authority.\nC:H - KASAN-confirmed slab use-after-free read of conn-\u003epreauth_info (kmalloc-96) via Preauth_HashValue and Preauth_HashId dereference; UAF on attacker-influenced freed heap memory enables arbitrary kernel memory disclosure through heap grooming.\nI:H - The UAF corrupts kernel heap state on a network-facing pre-auth path; freed preauth_integrity_info objects can be reallocated via heap spraying to obtain arbitrary write or control-flow hijack primitives beyond the immediate hash-buffer access.\nA:H - Concurrent UAF read of freed conn-\u003epreauth_info during smb3_preauth_hash_rsp() causes kernel oops or panic (KASAN-confirmed); even without full exploitation the race reliably triggers high-severity denial of service on the server."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-17T05:44:02.758Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/c7bef84740d1d57848c74f6f5b996606e43ea4fe"
        },
        {
          "url": "https://git.kernel.org/stable/c/d0a469122e7bf8338fec1949fb1e8e1290ed8caa"
        },
        {
          "url": "https://git.kernel.org/stable/c/7470511d085af1c7a043a60e53d52b512d5a10b1"
        },
        {
          "url": "https://git.kernel.org/stable/c/16a1ecf39c217e3d164bd32ef2a4f650abc067fa"
        },
        {
          "url": "https://git.kernel.org/stable/c/77bb0bbfcc4e777ca653174689e5e363f8ee63d1"
        },
        {
          "url": "https://git.kernel.org/stable/c/1c89da3baa2b1f269178afa87dc30479b8535776"
        },
        {
          "url": "https://git.kernel.org/stable/c/0c054227479ed7e36ebccb3a558bc0ef698264f6"
        }
      ],
      "title": "ksmbd: fix use-after-free of conn-\u003epreauth_info in concurrent SMB2 NEGOTIATE",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-72422",
    "datePublished": "2026-08-15T05:56:41.090Z",
    "dateReserved": "2026-08-09T03:40:39.927Z",
    "dateUpdated": "2026-08-17T05:44:02.758Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

{
  "affected": [],
  "aliases": [
    "CVE-2026-72422"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-08-15T06:22:15Z",
    "severity": "CRITICAL"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: fix use-after-free of conn-\u003epreauth_info in concurrent SMB2 NEGOTIATE\n\nconn-\u003epreauth_info is shared connection state (struct\npreauth_integrity_info, kmalloc-96) that is allocated and freed by the\nSMB2 NEGOTIATE handler and read by the response send path.\n\nsmb2_handle_negotiate() allocates conn-\u003epreauth_info, and on a\ndeassemble_neg_contexts() failure kfrees it and sets it to NULL. Both the\nallocation and the free/NULL happen under ksmbd_conn_lock(conn) (the\nconnection srv_mutex), which is held across the whole handler body.\n\nThe response send path smb3_preauth_hash_rsp(), called from the send:\nblock of __handle_ksmbd_work(), reads conn-\u003epreauth_info and dereferences\nconn-\u003epreauth_info-\u003ePreauth_HashValue (via\nksmbd_gen_preauth_integrity_hash()) without taking conn_lock. When a\nclient drives two SMB2 NEGOTIATE requests on the same connection, one\nworker can free conn-\u003epreauth_info on the failing-negotiate path while a\nconcurrent send-path worker is reading it, producing a slab\nuse-after-free read (KASAN-confirmed).\n\nThe send-path read tested conn-\u003epreauth_info for NULL but raced with the\nfree that occurs between the NULL check and the dereference, so the NULL\nguard alone does not close the window.\n\nSerialize the NEGOTIATE-branch read in smb3_preauth_hash_rsp() under\nksmbd_conn_lock(conn) and re-check conn-\u003epreauth_info inside the lock.\nBecause the negotiate handler holds conn_lock across its kfree + NULL\nassignment, a reader that also takes conn_lock either runs fully before\nthe allocation or fully after the NULL store, and can never observe the\nfreed-but-not-yet-NULLed pointer. ksmbd_gen_preauth_integrity_hash()\ntakes no locks itself (it only computes a SHA-512 over the buffer), so\nno lock-ordering inversion is introduced, and conn_lock is a sleepable\nmutex which is safe on this send path (it already performs network I/O).",
  "id": "GHSA-2r52-5q5c-m3mp",
  "modified": "2026-08-17T06:33:29Z",
  "published": "2026-08-15T06:32:24Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-72422"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/0c054227479ed7e36ebccb3a558bc0ef698264f6"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/16a1ecf39c217e3d164bd32ef2a4f650abc067fa"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/1c89da3baa2b1f269178afa87dc30479b8535776"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/7470511d085af1c7a043a60e53d52b512d5a10b1"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/77bb0bbfcc4e777ca653174689e5e363f8ee63d1"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/c7bef84740d1d57848c74f6f5b996606e43ea4fe"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/d0a469122e7bf8338fec1949fb1e8e1290ed8caa"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}